HP is also nice for soaking magic damage which looks like a bit of a weakness for druid tanks.

Dodge is active mitigation. If you are stunned or incapacitated, it's useless. There's a fair amount of stuns so far from what I've seen in TBC instances. Also, I think dodge requires you be facing your opponent. I know that's the case in PVP, not sure about PVE (want to kill a rogue with evasion up? Stun him or get behind him). I don't know for sure since I'm usually also trying to block and parry, which I know for a fact require you face the right way. That's a problem if you get feared or attacked from behind.

The other thing to consider is what dodge does to overall incoming crit/crush damage. I don't think we ever conclusively determined what the "order" of the combat table was, but if dodge doesn't do anything to reduce the incidence of a crit/crush, then it isn't as valuable as pure AC mitigation is. AC will apply to all of those hits whereas dodge will only apply to "hits". I know when I first started raiding, if I didn't push dodge/parry/miss over 100% with evasion, when I did get hit, it was a guaranteed crit/crush. It made for a very spikey damage curve. I'd get hit 15% of the time, and every single one was for 150-200% damage.

I was under the impression, that Dodge works also from behind. Your trick against the Rogues works probably because you stunned him...

I think I've read it that avoidance trumps crushing blows, like you pretty much stated from your own experience. Which would make the Dodge trinket a very valuable addition since it would indeed reduce the chance of crushing blow, given high enough avoidance to start with.

dodge not working from behind with evasion is/was a bug. dodge works from behind, parry/block does not. "miss" also works from behind.

If incapacitated and unable to dodge, parry, or block, high AC trumps every trick in a warrior's bag. Both will be hit and crushed, one will take 12% less damage on those hits.

I wasn't making a point about warrior vs druids, I was just saying AC is the bees knees for mitigation. Don't get fooled into thinking 1% avoidance = 1% AC mitigation. The mechanics generally favor AC.

Sorry if I interpreted it that way. I just spent a long time on vent listening to some warriors talk about loot and they were far, far to focused on +defense and stamina and not mentioning agility and AC enough. AC is huge and people often don't realize it because they don't realize that going from 55% to 56% in the character sheet isn't 1% less damage, its 2.2% less. Druids are more attuned to this concept and often overlook dodge%.

In an environment where you expect a constant stream of healing, AC becomes even more important -- for all tanks.

From my experiences so far, reaching crit immunity has been well worth it. At the moment I'm sitting on about 15k HP (fort, motw, no kings, no blood pact), 24k AC, 29% dodge and crit immunity. With threat having been touch and go in 5 mans recently, I was rather nervous about switching in 2 pieces of heavy clefthoof for Kara last night with their lack of offensive stats. However threat was fine and there was no problems in this area.

Firstly, thanks a lot for all the data. This is an amazing collection of very useful info!

I haven't seen much discussion about the weapon slot though. I'm having a hard time deciding between something with +armor (say [Braxxis' Staff of Slumber]] or eventually [Earthwarden]]) vs something with AP for threat, a bunch of Stamina and maybe some agi for dodge (say [Staff of Beasts]).

I've discussed this a couple times with a few tanks (Bears and Warriors alike) and the argumen goes both ways. Some argue that the extra mitigation from the armor will allow you to take far less total damage, straining the healers less and allowing their mana to last longer and therefore keep you alive longer. Others (me included) tend to say that your chances of dying from spike damage is much higher than dying from healers running out of mana, so the extra stamina is more beneficial.

I know stamian vs. armor has been talked a lot before, but with the case of the weapon slot it seems to be very specific values (~500 armor vs 50 stamina). Hopefully this isn't too repetitive of a discussion.

I agree with the sentiment of "your chances of dying from spike damage is much higher than dying from healers running out of mana" but your conclusion is wrong. If you argue like that, you do not compare AC against Stamina - because they effectively are one thing due to synergy. The more HP you have, the more your AC counts. And the more AC you have, the more your HP is worth. Usually when people argue about dying to spikes vs dying from healers going OOM they compare an AC/Sta heavy set vs an Avoidance set. Yes, the more Avoidance you have, the more worth your HP and to a slightly lesser extent AC (the more Avoidance you have, the less AC is worth since you get less often which means you get to use your AC less often), however compared to AC/Sta your Avoidance is not something to rely on. Like it was said before, if you get stunned your avoidance is set to 0% (except misses against you) and if you are unlucky it doesn't do shit. Avoidance is just something you can stack up on after getting your minimum set of HP and Armor for a specific boss to easen up the load of damage taken but usually the healers will precast the heals anyway so the benefit is less than you think.

Honestly, I wouldn't be surprised if raids would prefer a tank with 0 avoidance and the ability to live through spikes over a tank with 80% avoidance and the chance to die to spikes at 1-2%. I have seen a tank drop dead in 3 seconds on bosses because of, how to say it, unlucky strings of special moves on him although he did take less overall damage than a comparable Bear that stacked AC/Sta. To be fair, said tank would have died due to lack of heals some times as well but he got lucky and avoided some attacks until heals resumed landing on him - but playing Dodge Roulette is not something I'd want.

Make of it what you will.

EDIT: Me sxx0r of spellzing

I'm not really sure I would say it's a "weakness" for a Druid tank, as much as it's a bit different. Predatory Instincts (15% chance to avoid AoE attacks) is an obscenely powerful talent for tanking most bosses and situations from what our Druid tanks are reporting. As I'm not a Druid tank (Warrior) I'm not sure what it all applies to, but they are saying it seems to apply to any AoE effect, including cleaves and spells. Provided that is correct, Bears get a huge boon towards basically having another 15% avoidance on Cleave, Shadowflame-esque abilities, and pulsing AE+RoF type attacks.

Avoidance does not trump crushing blows per se...this is a common misconception. Most people think that Block% is good on a Warrior simply because it "cancels crits and crushing blows", when that is simply not the case at all. Crushing is its own slot in the combat table, meaning the combat table from bottom to top looks something like this:

Miss/Parry/Dodge/Block/Crit/Crush/Hit

As it is a table, things on the bottom push things on the top off... however you would need tons and tons of avoidance to ever push crits/crushing blows off the table. Even presuming you are uncrittable, you still have a 15% chance to be crushed at all times, unless you push crushing blows off the table. This would require 85% total avoidance, though, which is usually impossible to get. (Note: As the original quoter said, that may not be the "exact" order of the combat table, but evidence seems to point to it being at least similar to that.)

(This is, incidentally, why people get the wrong impression that block itself is what is good for Warriors...when, in reality, it is simply the fact that the Shield Block skill adds so much to the combat table that crushes get pushed off. It is the Shield Block skill, not blocking itself that prevents crushes.)

PI is a great talent, no doubt, and it's definitely a must have for serious Bear tanks (same goes for Primal Tenacity with the same reasoning). But it is in no way comparable to (Improved) Defensive Stance. It's the same argument about AC/Sta vs Avoidance once again; one guarantees mitigation while the other can potentially negate 100% to 0% of damage taken. While it's true that on average both imp. D stance and PI mitigate roughly the same amount of damage on AoE based magical damage fights a Druid just can't gear around having PI while a Warrior can gear around having D stance. If you know how much magical burst a boss can throw your way you can substract 16% of it and have your minimum HP right there. Fill up the rest with resist gear and you are golden.
A Druid can't just substract 15% and get this required HP like that, he has to go with the worst case of PI never proccing just like the Warrior goes with the worst case of "only" having Imp. D stance.

Grace of air totem probably. After the improved talent, blessing of kings, and survival of the fittest it gives ~100 agility, which is 6.8% dodge. A major agility potion is another 2.7 dodge if you didn't factor that in already